The calorific value describes the energy content of the biomass per unit of mass, in megajoules per kilogram (MJ/kg). Calorific value may be expressed as either gross or net calorific value; on an as-received (the moisture content as observed) or dry basis; including ash or ash-free. In the table and chart below, the calorific value is expressed as gross calorific value on a dry basis (GCV db).
The values shown below for ash content, hydrogen content and nitrogen content are averages drawn from the database using the species and partition selection menus. These values are subsequently used to calculate the gross calorific value on a dry ash free basis (GCV (dab)), and the net calorific value (NCV) on a dry basis and as received.
Net calorific value is the calculated value of the energy of combustion for unit of mass of a fuel burned in oxygen in calorimetric bomb under such conditions that all the water of the reaction products remains as water vapour at 0.1 MPa. The net calorific value can be determined at constant pressure or at constant volume, both are presented below.
The moisture content parameter used in the calculation of net calorific values (as received) is determined by the user selection.